Ask HN: What weird or hard problems are you trying to solve?

Would Fremen Stillsuits like in the Dune novels actually be possible?

These suits allow to survive for weeks out in the deep desert, by catching and recycling all of the body's lost water. Making sure no perspiration can escape is doable. Filtering the sweat to produce clean, salt-free water should be possible as well - membranes for water desalination do already exist today. To have all the required pumping action provided through walking and breathing is a mechanical problem that should be theoretically solvable. The big, unsolved problem I see, is heat.

The book says that the suit's layers closest to the skin allow the sweat to evaporate and thus provide cooling to the body. But the water then has to condensate again somewhere. From my (limited) understanding of the laws of thermodynamics, the amount of extra heat created through condensation, should be exactly equal to the amount of cooling the evaporation provides making the whole cycle a zero-sum affair. But for this cycle to work in the first place, the skin would have to be of higher temperature then the layer where the condensation occurs. If the desert heat is above body temperature, we'd need some sort of heat pump like in a fridge. Using changes in pressure and density (through a compressor) you could cool the suits' inside below body temperature, while heating the outside above ambient temperature - which is necessary to actually give off heat to the outside.

Those compressors are heavy and powerhungry though, and you'd need additional high pressure water lines through the suit - increasing the bulk of the whole thing considerably. Future technology might be more miniaturized and more energy efficient, but still... Maybe piezoelectric/thermoelectric cooling (exploiting the Peltier effect) would be a better choice for a suit like this. Then you'd have a light inner layer that allows for air circulation - so that the sweat can evaporate on the skin, and condensate again at the thermoelectrically cooled middle layer - where it's collected and pumped away to the membrane filters and catchpockets.

The outer layer of the suits would have to be made of flexible solar cells, in order to provide the electricy required for the cooling of the middle layer. Not sure if that could work though. Those solar cells produce a lot of heat on their own, and they sit right on top of the heat-producing side of the thermoelectric cooling. And the sun burning down on it as well - that's a lot of heat right there at the outer layer. I don't think thermoelectric cooling can overcome that high a temperature difference. It works best, when the temperature difference between the cool side and warm side is pretty small.

I’m building an on-premise alternative to Google Photos[1]. Started working on this because it’s not okay for Google to have unencrypted access to and own all my memories.

[1] https://youtube.com/watch?v=b5XN5GMmc6I

Server side there's already NextCloud, which is pretty mature. https://github.com/nextcloud/photos

Nice! Are you aware of https://github.com/hooram/ownphotos? No affiliation, I'm just interested in using something like this, I'm not sure how actively it's being worked on (it was sort of a 'functional demo' last I saw, but not quite usable).

I have a theory that, individually, people fundamentally disagree less than they think they do. And in real face to face meetings, they are willing to disagree about a topic without killing each other. They talk around points of disagreement. Eg: me, when I'm talking to my grandmother.

The problem is that online people tend to polarize into factions during complex discussions. The more heated the discussion, the more polarized they become. Eventually it becomes impossible for either side to be self critical, or to cede a point to the other side no matter how true it may be.

"B" says "the sea is made of saltwater". A moderately reasonable "A" agrees. Mistake! The "A" group accuse them of being pro-B or anti-A. Suddenly, the idea that the sea is saltwater becomes an "B dogwhistle". A cunning trick! At this point, the "A" group adds 'saltwater sea' to their list of unacceptable opinions, and the policing of everyday language and opinion is in place. That's when the notion of defending free speech gets questioned. How can you police language if people defend free speech?! It won't do! So now free speech is a dogwhistle too. Add it to the list! There is no possibility for constructive dialogue, no matter how sensible, kind and cool-headed it tries to be. Disagreement with dogma or talking to the opposition are offences. New rules: "Don't follow an A on Twitter". Guilt by association. Next up: let's use the abuse/reporting system to ban individuals. Eventually, online systems that were supposedly designed for communication and conversation have become tools for suppression and virtue monitoring.

While anonymity itself will help people to own up to an opinion that they might be otherwise afraid to voice, unless there are no usernames at all it will be possible to track an individual across the system and figure out "which side they're on". Then you'll be able to figure out if their comments are acceptable or hatespeech without having to properly consider them.

Don't get me wrong, I'd love to see this happen, but I think it requires a lot of work. Deduplication of points made, automatic detection of logical fallacies via natural language processing, personal dictionaries with auto-translation of terms (eg: an acceptable word to you might be a slur to someone else - if the word has a genuine meaning, auto-translate to a non-slur). That would avoid having people point and scream and claim moral victory because of a word infraction, instead of hashing thing out properly.